The splitter wire is rarely the limitation and that one is a reputable product. I have used them for several years. The fan controller providing the power to the fans is more likely to be the limiting factor. Most motherboard headers are 1.0A. The LLs are 0.30A each, so two on one header is not a problem. If you are planning to connect them to something else, make sure you find out the current limit for that specific device, but it would be shocking to find anything less than 1.0A.